Nickel aquatic organisms

Nickel is toxic to aquatic organisms at levels typically observed in POTW (publicly owned treatment works) effluents ... 

Many aquatic organisms exhibit an ability to concentrate a variety of trace elements and this ability has been identified as a function of the tendency of the elements to be complexed by ligands (159). The alkaline earth metals are poorly com-plexed in relation to the transition metals, copper, nickel, cobalt, zinc and manganese. The actinides should be regarded as members of an intermediate group. It has been suggested by Martin (160) that at least five mechanisms may regulate the uptake of metals by marine biota. These are... 

Two studies concerning levels in voles and rabbits living on sludge-amended land did not indicate any accumulation of nickel in these herbivores or in the plants they fed upon (Alberici et al. 1989 Dressier et al. 1986). The lack of significant bioaccumulation of nickel in aquatic organisms, voles, and rabbits indicates that nickel is not biomagnified in the food chain. 

Nickel levels in terrestrial and aquatic organisms can vary over several orders of magnitude, according to the species and environmental factors [9,10]. Typical atmospheric nickel levels range from about 5 to 35 ng/m at rural and urban areas [3]. This does mean an average daily uptake of nickel between 0.1 and 0.7 xg by inhalation. Drinking water from public water supplies usually contains less than 20 p.g Ni/liter but occasionally nickel may be released from fittings in concentrations up to 500 (xg Ni/liter [11]. 

Table 6.7 (continued) Nickel Effects on Selected Aquatic Plants and Animals Taxonomic Group, Organism, Dose,... 

It can be seen from Figure 11 that, by the appropriate choice of the equilibrium concentration of chloride ion in the aqueous phase, separations between certain pairs of metals can be made, for example between copper(II) and manganese(II) at a chloride concentration of 3.0 M, and between cobalt(II) and nickel(II) at a chloride concentration of 6 to 8 M. Furthermore, the metals can be stripped from the loaded organic phase by being contacted with an appropriate volume of water so that the equilibrium concentration of chloride ion in the strip liquor lies on the lower portion of the extraction curve, where substantial aquation of the extracted chlorometallate occurs... 

The overall effect of estuarine water on the hydridisation process is thus one of reducing yields of the three tin species tested. It is expected that not only the dissolved and particulate organics and chloride influence formation of Sn-H bonds, but that other aquated metal ions play an important role, too. Several workers have reported that, for example, arsenic(III), arsenic(V), copper(II), nickel(II), mercuiy(II), lead(II) and silver(I) interfere by unknown means at low concentrations [702,753],... 

Hanson AKJ and Quinn JG (1983) The distribution of organically complexed copper and nickel in the mid-Atlantic Bight. Canadian Journal of Fisheries and Aquatic Sciences 20 151-161. 

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